Introduce Measuring in space Light Year Distance light

Introduce

Measuring in space • Light Year – Distance light travels through space in one year • About 300, 000 km/s • Or 9. 5 trillion km/year • Astronomical Units (AU) • Distance from Earth to the sun • Which is about 150 million km.

Solar system • A solar system is a collection of large and small bodies that orbit our central star, the sun. • Within our solar system are planets. • Planets are spherical bodies that orbit the sun that are larger than the other bodies that are in our solar system.

Solar system • Orbiting most of our planets are smaller bodies called moons. • The rest of our solar system is made up of other small bodies that include: • • dwarf planets Comets Asteroids Meteroids • There are up to a trillion small bodies in the solar system.

Stars • A star is a celestial body that is composed of gas and emits light. • Most are made of hydrogen and helium • Stars create energy through nuclear fusion • This energy is released as light and radiation

Our Sun • Sun • The sun is a medium sized star. • The sun is also a relatively cool star at about 5, 500 C on its surface. • The next closest star is Proxima Centauri and is 270, 000 times farther away from Earth than the sun is.

Star Clusters • The smallest space structure is a solar system. • Next largest is a star cluster • A group of stars bound together by gravitational attraction • Star clusters may contain a couple hundred to thousands of stars. • The next largest is a galaxy.

Galaxy • Our solar system is located in outer arm or the edge of the Milky Way Galaxy. • The Milky Way Galaxy is a single star spiral galaxy. • Other types of galaxies include • Elliptical galaxies • Look like spheres with no “arms” • Irregular galaxies • No pattern blobs • These are very active areas for star formation

The Universe • The universe can be defined as space and all the matter and energy in it. • Within the universe there are clusters of galaxies called super clusters • These super clusters may contain several thousand galaxies • There also large areas where very little matter exists called voids. • The structure looks like a spider web. • web = clusters • Space between web = voids

Closing Questions: • Answer the following questions on your closing section on the warm up using complete sentences: 1. How could you describe your location in space? 2. What are three new things you learned today? 3. What are three things you still want to know about space?